Abstract
Background: The Chemoattractant Receptor-homologous molecule expressed on T-Helper type 2 cells (CRTH2) is not only expressed on Th-2 cells but also on eosinophils, basophils and T-cytotoxic cells (Tc2) cells. Its ligand PGD2 is produced in the lung by mast cells upon activation and subsequently activates cells that express CRTH2. CRTH2 antagonists have shown an effect on lung function and airway eosinophilia in one RCT with severe asthma patients and could be more effective in a targeted patient population with high levels of peripheral blood cells that express CRTH2 receptor.
Methods: Blood was taken from 8 patients with severe asthma (according to ERS/ATS guidelines) and airway eosinophilia (by sputum analysis) and from 5 healthy controls. CRTH-2 expression was measured on eosinophils, basophils, Th2 cells and Tc2 cells by flow cytometry.
Results: Severe asthma patients have higher levels of CRTH-2 positive cells (P<0.001), with significantly higher levels of blood eosinophils and a higher (NS) pattern in basophils levels compared to healthy controls.
Conclusion: Overall, our preliminary data shows that patients with severe asthma have high levels of CRTH2 positive cells in peripheral blood irrespective of their allergic status. Eosinophil levels are significantly higher in asthma patients and other populations show interesting higher trends.
- Copyright ©ERS 2015
